JP2020202433A - Metamaterial antenna - Google Patents

Abstract

To provide a technology that can facilitate design adjustment and post-manufacturing repair work that achieve both electromagnetic interference resistance, miniaturization of an antenna, and high interest rate of the antenna by an antenna element alone.SOLUTION: A metamaterial antenna 1 includes an LC network unit 30 that has a capacitor CLC and an inductor LLC with an antenna radiation unit 20 as a left-hand transmission line, and is set to have a removal band for interfering waves. The antenna radiation unit 20 includes first and second radiator lines 21 divided and formed on a first surface of a dielectric substrate 10 so as to have a predetermined interval d, and on the back surface of the dielectric substrate 10, a capacitor line 30a is formed so as to have a MIM capacitor surface range 30b that overlaps with the first and second radiator lines 21 in a plane view. The radiator line 21 and the MIM capacitor surface range 30b form a capacitor CLC having a MIM structure.SELECTED DRAWING: Figure 1

Description

The present invention relates to, for example, a metamaterial antenna mounted on a satellite.

The applicant has installed the L-band synthetic aperture radar "PALSAR-3" and the high-performance satellite-mounted AIS "SPAISE3" on the advanced radar satellite (ALOS-4), and observed them in a coordinated manner. We are developing a system for ocean monitoring (see Non-Patent Document 1).

When mounting several types of mission antennas on a satellite and securing the antenna opening length required to ensure performance, each antenna has a dedicated deployment structure in the past, and the system is designed within the range that is not affected by electromagnetic interference or thermal interference. Is being done. Each antenna element tends to be as simple as possible in order to reduce the design cost and utilize the actual results. In that case, the filter configuration to the receiving circuit in the subsequent stage of the antenna corresponds to it, and the antennas for different purposes have a sufficient distance. It is secured and installed. For this reason, the potential of the entire satellite system is often not maximized. For example, in such a satellite system, the L-band SAR antenna panel and the "SPAISE3" deployable antenna each have a dedicated deployable structure, and the antenna deployable range is limited when it is desired to secure the antenna aperture length as much as possible.

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In the background of these problems, the antenna element alone is required to have electromagnetic interference resistance, miniaturization of the antenna, and high interest rate of the antenna. That is, it is desirable that an element size of half a wavelength or less secures sufficient antenna efficiency at the reception frequency, and that an antenna element alone can suppress an interference frequency, for example, close to 20 dB.

In view of the above circumstances, an object of the present invention is to facilitate design adjustment and post-manufacturing repair work for ensuring electromagnetic interference resistance, miniaturization of the antenna, and securing of antenna efficiency with the antenna element alone. Is to provide the technology that can be done.

In order to achieve the above object, in the present invention, a metamaterial antenna is adopted, and the metamaterial antenna has an antenna radiating portion and a capacitor and an inductor having the antenna radiating portion as a left-handed transmission line, and is used as an interfering wave. On the other hand, it is provided with an LC network unit set to have a removal band.

In the present invention, various frequency characteristics of a metamaterial antenna are applied, and an LC network unit having a capacitor and an inductor whose antenna radiating part is a left-handed transmission line is set to have an elimination band for interfering waves. It is possible to facilitate design adjustment and post-manufacturing repair work that secures electromagnetic interference resistance of the antenna element alone, miniaturizes the antenna, and secures antenna efficiency. In the design of the elimination band, for example, bandgap formation and cutoff frequency setting are used.

The metamaterial antenna according to the present invention has a dielectric substrate, and the antenna emitting portion is formed by dividing the first surface of the dielectric substrate so as to have a predetermined interval. A first having two radiator lines, the capacitor being arranged on the second surface side of the dielectric substrate to have a first region overlapping the first and second radiator lines. It has a capacitor line of. For example, the LC network unit has an area adjusting unit for adjusting the area of the first region so as to have a removal band for the disturbing wave.

At the design and trial stage, it is a heavy workload to achieve electromagnetic interference resistance, miniaturization of the antenna, and high interest rate of the antenna by itself, and the development cost for each antenna is currently high. Is mostly spent on unfolding structures. In the present invention, in a metamaterial antenna having a complicated structure, it becomes easy to adjust so as to have a removal band for an interfering wave, and for example, advanced design / trial work can be performed flexibly and easily. ..

In the present invention, a capacitance is provided between a ground conductor arranged on the second surface side of the dielectric substrate so as not to overlap the antenna radiation portion, both ends of the antenna radiation portion, and the ground conductor. It has a second capacitor line to be provided. This makes it easy to adjust the impedance characteristics and change the radiation pattern.

The metamaterial antenna of the present invention has an antenna radiation having a dielectric substrate and first and second radiator lines formed by dividing the first surface of the dielectric substrate so as to have a predetermined interval. A unit and a first capacitor line arranged so as to have a first region overlapping with the first and second radiator lines are provided on the second surface side of the dielectric substrate. This facilitates the adjustment of the LC network, and facilitates design adjustment and post-manufacturing repair work that secures electromagnetic interference resistance of the antenna element alone, miniaturizes the antenna, and secures antenna efficiency. ..

In the metamaterial antenna of the present invention, the dielectric substrate, the antenna radiating portion formed on the first surface of the dielectric substrate, and the antenna radiating portion overlap on the second surface side of the dielectric substrate. It is provided with a ground conductor arranged so as not to be formed, and a second capacitor line having a capacitance between both ends of the antenna radiation portion and the ground conductor. As a result, the degree of freedom in designing the LC network can be improved, and the impedance characteristics can be adjusted by the antenna radiation end.

According to the present invention, further flexibility is added in the design adjustment and post-manufacturing repair work in which the antenna element alone secures electromagnetic interference resistance, miniaturizes the antenna, and secures antenna efficiency in parallel, and the radiation pattern of the antenna. Can also be changed.

It is an exploded perspective view which shows the structure of the metamaterial antenna which concerns on one Embodiment of this invention. It is a top view of the metamaterial antenna shown in FIG. 1 as seen from above. It is a circuit block diagram of the metamaterial antenna shown in FIGS. 1 and 2. It is an antenna reflection characteristic at a feeding point which shows an example of the pass band and the removal band of the metamaterial antenna shown in FIGS. 1 to 3. It is an exploded perspective view which shows the structure of the metamaterial antenna which concerns on other embodiment of this invention. It is a top view of the metamaterial antenna shown in FIG. 5 is a circuit configuration diagram of the metamaterial antenna shown in FIGS. 5 and 6.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing a configuration of a metamaterial antenna according to an embodiment of the present invention. FIG. 2 is a plan view of the metamaterial antenna shown in FIG. 1 as viewed from above. FIG. 3 is a circuit configuration diagram of the metamaterial antenna shown in FIGS. 1 and 2.

The metamaterial antenna 1 has a dielectric substrate 10, an antenna radiation unit 20, an LC network unit 30, and a ground conductor 40. In FIG. 1, the capacitor line 30a, the inductor line 32, and the ground conductor 40 constituting the LC network portion 30 arranged on the back surface of the dielectric substrate 10 are shown by being separated from the dielectric substrate 10.

The antenna radiating portion 20 has a radiator line 21 formed on the surface of the dielectric substrate 10 by dividing the antenna so as to have a predetermined interval d. The metamaterial antenna 1 according to this embodiment has a radiator line 21 divided into six, and a feeding point 11 is provided between the central radiator lines 21.

On the back surface of the dielectric substrate 10, a capacitor line 30a is formed so as to have a MIM capacitor surface range 30b as a first region that overlaps with the radiator line 21 in a plane. The radiator line 21 and the MIM capacitor surface range 30b form a capacitor C _LC having a MIM structure. In FIG. 2, the portion shown by the dotted line is shown to be arranged on the back surface of the dielectric substrate 10.

The LC network unit 30 has a capacitor line 30a and an inductor line 32, thereby forming a capacitor C _LC and an inductor L _{LC in} which the antenna radiation unit 20 is a left-handed transmission line, and a band for removing interference waves. The values of the capacitor C _LC and the inductor L _LC are set so as to have.

In the present embodiment, the area adjusting unit 31 is provided by adjusting the area of the MIM capacitor surface range 30b by adjusting the area of the radiator line 21. The area adjusting unit 31 is typically configured by adjusting the area of the radiator line 21 corresponding to the MIM capacitor surface range 30b at the time of designing, and is further formed on the surface of the dielectric substrate 10 after, for example, a trial production. The area is adjusted by removing a predetermined portion of the exposed radiator line 21, such as the end, or in some cases by adding a conductor corresponding to the line.
The area of the MIM capacitor surface range 30b may be adjusted by removing a predetermined portion of the capacitor line 30a or, in some cases, adding it.
The inductor _LLC may be adjusted so as to have a removal band with respect to the interfering wave, but adjusting the capacitor C _LC makes the adjustment work after the trial production easier than the case of adjusting the inductor _LLC. is there. The radiator line 21 for adjusting the capacitor C _LC is exposed on the surface of the dielectric substrate 10, and the capacitor C _LC can be adjusted simply by removing the end of the radiator line 21. That's why.

The inductor _LLC has an inductor line 32 formed on the back surface of the dielectric substrate 10 and inserted between the capacitor line 30a and the ground conductor 40. The inductor line 32 is typically configured to be continuously folded back to have a predetermined inductor wardrobe.

The ground conductor 40 is formed, for example, on the back surface of the dielectric substrate 10 so as not to overlap the antenna radiation portion 20 when viewed in a plane.

In the metamaterial antenna 1 configured as described above, by adjusting the MIM capacitor surface range 30b constituting the capacitor C _LC of the LC network portion 30, it is possible to give any phase characteristic to an arbitrary frequency. For example, when the L-band SAR antenna and the AIS receiving antenna are mounted on the satellite, the AIS receiving antenna is the metamaterial antenna 1 according to the present embodiment, and as shown in FIG. 4, the passing band becomes the AIS frequency and is removed. The band is designed to be the L band SAR which is the interference frequency, and the area adjusting unit 31 is adjusted at the time of trial production or the like. As a result, it is possible to facilitate design adjustment and post-trial repair in which the antenna element alone secures electromagnetic interference resistance, miniaturizes the antenna, and secures antenna efficiency.

In FIG. 4, the horizontal axis represents the frequency and the vertical axis represents the reflection characteristic in the feeding portion. The solid line “with CRLH” indicates the reflection characteristics when the LC network unit is added, and the dotted line “w / o CRLH” indicates the antenna characteristics when only the antenna radiation unit 20 without d in FIG. 1 is provided. Shown. N and N ₀ indicate each resonance order.

Having a resonance point that is more negative than CRLH makes it possible to reduce the size of the antenna.

The AIS frequency can be set to the left-handed passband and the right-handed passband, and the elimination band can be designed with a band gap or a cutoff, and the present invention does not exclude such a combination.

In the metamaterial antenna 1 according to the present embodiment, in particular, the area is adjusted by forming a capacitor _CLC having a MIM structure with a MIM capacitor surface range 30b composed of a radiator line 21 formed by dividing and a capacitor line 30a. By using the part 31, the left-handed capacitance capacity can be secured to a large capacity and easily changed by reworking at the time of design and after trial production, and each capacitance chap (for optimization of amplitude characteristics) when applied as a leakage wave antenna. The method of gradually changing the dimensions) can also be freely set.

Further, as a result, in the metamaterial antenna 1 according to the present embodiment, the antenna size and structure in which the target frequency can be easily estimated can be camouflaged. For example, when only the surface is viewed, it can be erroneously recognized as a non-feeding one-dimensional linear array antenna at a high frequency several times higher than the desired frequency. Further, depending on the LC network on the back surface of the dielectric substrate 10, a plurality of target frequencies can be adjusted, and the antenna application cannot be easily estimated.

Further, in the metamaterial antenna 1 according to the present embodiment, since the LC network pattern on the back surface is shielded from sunlight and the like, it is possible to suppress deterioration and fluctuation of characteristics due to the environment such as temperature rise, and to reduce stress due to temperature change and to be reliable. The sex can be improved.

Further, the metamaterial antenna 1 according to the present embodiment can be configured without a through hole or the like while adding a large-capacity conductance by using a MIM capacitor.

FIG. 5 is an exploded perspective view showing the configuration of the metamaterial antenna according to another embodiment of the present invention, and FIG. 6 is a plan view seen from the upper surface of the metamaterial antenna shown in FIG. FIG. 7 is a circuit configuration diagram of the metamaterial antenna shown in FIGS. 5 and 6.

The metamaterial antenna 1'according to the embodiment is first shown to have a capacitor line 21e having a capacitance between both ends of the antenna emitting portion 20 and the ground conductor 40. Is different. The capacitor lines 21e shown in FIGS. 5 and 6 extend from the ends of the radiator lines 21 at both ends of the antenna radiating portion 20, and the extending capacitor lines 21e overlap with the ground conductor 40 in a plane view. in constituting the capacitors _{C e} of the MIM structure. By adjusting the capacitor C _e, it is possible to provide an arbitrary phase characteristic to an arbitrary frequency in the same manner as LC network unit 30, in addition becomes easy to adjust the impedance characteristic, it can be changed in the radiation pattern It becomes.

The capacitor line 21e is not limited to the configuration shown in FIGS. 5 and 6, for example, a line (capacitor line) extends from the ground conductor 40, and the extended line overlaps the capacitor line 21e in a plane view. it may constitute the capacitor _{C e} of the MIM structure by.

A line (capsule line) is extended from the ground conductor 40 without extending the line from the end of the radiator line 21 at both ends of the antenna radiation unit 20, and the extended line extends from both ends of the antenna radiation unit 20. of may be a capacitor C _e of the MIM structure by overlapping when viewed in the end in a plan view of the radiator line 21.

The present invention is not limited to the above-described embodiment, and various modifications and applications are possible within the scope of the technical idea of the present invention.
For example, in the above embodiment, the radiator line 21 is divided into six, but the number of divisions may be less or more.
In the above embodiment, the configuration having the left-handed capacitor and the inductor is shown, but the right-handed capacitor and the inductor may be mixed.
In the above embodiment, an example in which the metamaterial antenna according to the present invention is adopted in a system in which an L-band SAR antenna and an AIS receiving antenna are mounted on a satellite has been described, but the metamaterial antenna according to the present invention is also used in other systems. It is possible to adopt.
In the above embodiment, an example in which the AIS is used as the pass band and the L band SAR is used as the removal band has been described, but the metamaterial antenna according to the present invention is adjusted so as to have two or more pass bands and removal bands. May be good.
In the metamaterial antenna according to the present invention, both ends of the antenna radiating portion and the ground conductor may be conducted through, for example, through holes, and a capacitance may be formed by a groove at any portion.

1, 1': Metamaterial antenna 10: Dielectric substrate 20: Antenna radiation unit 21: Radiator line 21e: Capacitor line 30: LC network unit 30a: Capacitor line 30b: MIM capacitor surface range 31: Area adjustment unit 32: Inductor Line 40: Ground conductor

Claims (6)

Antenna radiator and
A metamaterial antenna having a capacitor and an inductor having the antenna radiating portion as a left-handed transmission line, and having an LC network portion set to have a removal band for interfering waves. Has a dielectric substrate,
The antenna radiating portion has first and second radiator lines formed by being divided so as to have a predetermined interval on the first surface of the dielectric substrate.
According to claim 1, the capacitor has a first capacitor line arranged so as to have a first region overlapping the first and second radiator lines on the second surface side of the dielectric substrate. Described metamaterial antenna. The metamaterial antenna according to claim 2, wherein the LC network unit has an area adjusting unit for adjusting the area of the first region so as to have a removal band for the disturbing wave. A ground conductor arranged on the second surface side of the dielectric substrate so as not to overlap with the antenna radiation portion,
The metamaterial antenna according to claim 2 or 3, further comprising a second capacitor line having a capacitance between both ends of the antenna radiating portion and the ground conductor. Dielectric substrate and
An antenna radiating portion having first and second radiator lines formed by dividing the first surface of the dielectric substrate so as to have a predetermined interval.
A metamaterial antenna comprising a first capacitor line arranged on the second surface side of the dielectric substrate so as to have a first region overlapping the first and second radiator lines. Dielectric substrate and
An antenna radiation portion formed on the first surface of the dielectric substrate and
A ground conductor arranged on the second surface side of the dielectric substrate so as not to overlap with the antenna radiation portion,
A metamaterial antenna including both ends of the antenna radiating portion and a second capacitor line having a capacitance between the ground conductor.

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